Vegetable pulp shredder screen having cutter blades



Dec. 6, 1949 D. B. VINCENT 2,490,564

VEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Filed Aug. 10, 19452-Sheets--Sheet 1 Dec. 6, 1949 D. B. VINCENT 2,490,564

VEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Filed Aug. 10, 19452 Sheets-Sheet 2.

awe/whom Rik/i!) Z. Vahce/rf May/Z26 Patented Dec. 6, 1 949 OFFICEVEGETABLE PULP SHREDDER SCREEN HAVING CUTTER BLADES Daniel B. Vincent,Tampa, Fla.

Application August 10, 1945, Serial No. 609,961

6 Claims.

The present invention relates to vegetable pulp shredding machines ofthe type used for shredding or comminuting citrus waste and the like forthe manufacture of stock feeds and the like, and more particularly to animproved screen for such machines, and aims generally to improveexisting devices of that type.

Citrus waste material is the peel, rag and seed or a mixture thereof ofcitrus fruits and is so called because it is the waste from citruscanning and processing plants. Much of this citrus waste material isprocessed by shredding, chemical treatment and drying to produce ahighly desirable stock and cattle feed. A typical process for theprocessing of citrus waste into such a stock feed is disclosed in myprior patent No. 2,215,944, granted September 12, 1940.

Heretofore, the citrus waste material, comprising the half or quartersections of grapefruit, oranges and the like, have generally beenshredded in a hammer mill, generally consisting of a rotor havingswinging or fixed blades of from to inch in thickness, adapted to forcethe material through an apertured metal plate or screen, the roundapertures of which may vary from to 1 inch or more in diameter,depending upon the desires of the user. These mills required arelatively great amount of power for operation as the material must bechurned in the mill until it finds an opening for discharge.Furthermore, the citrus waste material heretofore shredded byconventional hammer mills has been very non-uniform in particle size,resulting in a feed containing a substantial amount of fine dust andmore or less large particles.

Such a non-uniform particle size material is very difiicult to dry.Citrus waste material contains approximately 80 to 85 percent moistureand is conventionally dried in a heated oven or dryer to a conditionWhere it contains 10 percent or less moisture. If the drying operationis maintained sufiiciently long to dry the large particles, the smallerparticles are burned. Hence, producers commonly adjust the drying to anintermediate particle size, and then screen off the fine, overdriedparticles, and the larger under-dried particles. The over-cooked finesmay be sold at a lower price or burned in the dryer furnace and thelarge under-dried particles are reground and again dried.

One of the primary objects of the present 111-. vention is the provisionof an improved citrus waste shredder and screen therefor that willproduce a highly desirable shredded product under substantially lesspower requirement than heretofore required.

A further object of the invention is the provision of an improvedshredder and screen therefor that will efiectively comminute citruswaste ma.- terial into particles of substantially uniformcross-sectional area, that may be more completely and uniformly dried inthe initial drying operation, and thus dispose of the necessity forscreening and re-shredding and drying of a portion of the product.

A further object of the invention is the provision of an improvedshredder and screen therefor for citrus waste material that will producea highly desirable shredded product of elongated particles ofsubstantially uniform cross-sectional area and substantially free fromdust. Such elongated particles tend to curl or crinkle during drying andoffer a relatively large surface to absorb water quickly when thematerial is used as a feed.

A still further aim and object of the invention is the provision of ashredder suitable for citrus waste material that will be simple inconstruction, efficient in operation and easily maintained in operativecondition and repair.

Other aims and objects of the invention will be apparent to personsskilled in the art to which the invention pertains from a considerationof the accompanying drawings and annexed specification, illustrating anddescribing certain preferred embodiments thereof.

In the drawings Fig. 1 is a rear elevation of a shredding machineembodying the invention, a portion of the outer casing being broken awayto show part of the mechanism in the interior thereof;

Fig. 2 is a side elevation of the machine shown in Fig. 1;

Fig. 3 is a transverse vertical sectional view of the machine as takenon the line 3-3 of Fig. 1;

Fig. 4 is an end elevation of one form of screen embodying theinvention;

Fig. 5 is an enlarged top plan view thereof;

Fig. 6 is an enlarged detail sectional view 50 thereof as taken on theline 66 of Fig. 5.

Fig. 7 is an end elevation of a modified form of screen;

Fig. 8 is a side elevation of a fragmentary portion of one of the screenknives used in the screen of the type shown in Fig. 'I.

Fig. 9 is an enlarged detail sectional view taken on the line 9-9 ofFig. 7;

Fig. 10 is a transverse sectional view of a further modified form ofscreen.

Referring more particularly to the drawings, the mill comprises ahousing l preferably in the form of a receptacle II and a removablecover or top |2 which may be hingedly connected as at I3 to thereceptacle so as to permit the cover to be swung upwardly to openposition, as shown in full lines Fig. 2, when access to the interior ofthe housing is required. The cover may be provided with a material inletl4 preferably above the receding side of a rotor, and the bottom of thereceptacle l0 may, if desired, be provided with an outlet l5 for thecontinuous discharge of shredded material. The inlet l4 has a retainingwall |4 adjacent the path of the rotor and preferably terminates in theplane of the rotor axis.

The receptacle [0 may be provided with spaced bearings |8 for a rotorshaft l9 having a pulley or other suitable means for applying rotationto the shaft I9. Preferably, the rotor shaft is mounted wholly in thereceptacle part II of the housing In, so that the cover |2 thereof maybe moved free from the shaft l9 and parts of the rotor mounted thereon.

The rotor comprises a series of blades disposed radially of the shaftand removably and reversibly connected thereto, and are preferablydisposed in planes normal to the axis of the shaft. These blades mayeither be cutting blades adapted to comminute the material fed to therotor from the inlet l4, or they may be beater blades adapted to feedthe material under pressure to a cutting screen, depending upon thedesired size of comminuted material.

According to an illustrated embodiment of the invention, the rotor maycomprise a plurality of supports 2|, herein shown in the form ofcircular discs, suitably secured to the shaft |9, as by a key 22, inspaced relation longitudinally of the shaft IS. The supports 2| providemountings for blade carriers 23 which are preferably spaced radiallyfrom the shaft and disposed in parallel spaced relation therewith. Theblade carriers are conveniently in the form of rods or bars extendedthrough aligned openings 23 in the supports near the outer ends orperipheral edges thereof, and may be releasably secured to the endsupports 2| by a suitable removable fastening, such as for example acotter pin or the like. The blade carriers 23 may also include bushingsor washers 26 surrounding the carrier and disposed between adjacentsupports 2| for properly positioning the blades 21 on the carriers 23.The blades 21 may be formed of elongated metal strips either of thinmetal with longitudinal cutting edges 28 or of thicker metal withrelatively blunt longitudinal feeding edges. The blades 21 arepreferably formed with a central aperture 30 to receive the bladecarrier 23, and the opposite ends of the blades are notched as at 3| toreceive a locking rod 32 extended through aligned openings 33 in thesupports 2|. Preferably the notches 3| are of larger radius or size thanthe central opening 30 so that they may fit over bushings 34 on thelocking rod 32.

The above described construction of rotor, blade carrier and lockprovides a suitable means for mounting the blades in the rotor for readyreplacement while the blade construction provides a means for readilyreversing the position of the blades and rendering available for useboth longitudinal edges thereof.

It will be noted in Fig. 3 that the blades of the rotor,moving in thedirection of the arrow, will engage the material in the inlet i4 andmove it toward the rear wall of the inlet, the bottom edge of whichpreferably is substantially in the plane of the shaft l9 or axis of therotor. Below the horizontal axis of the rotor is a screen 38, preferablysemi-circular in transverse section, one upper edge of which is insubstantial continuation of the rear wall of the inlet, the said screenpresenting a series of closely spaced substantially semi-circular knivesslightly spaced from the paths of the rotor blades and extendingthroughout a substantial portion of the rotation thereof, for examplethroughout approximately 180 degrees of the movement of the rotorblades.

The screen may embody one of several different constructions shown inthe drawings, and preferably includes a frame replaceably mounted in thehousing container H and including semicircular end members and siderails between which are mounted a longitudinal series of closely spacedsubstantially semi-circular knives having cutting edges closely adjacentto and following the path of the blades throughout a substantial arc ofthe travel thereof.

Referring more particularly to Figs. 4 to 6 inclusive, the screencomprises substantially semicircular end sections 39 and longitudinalside rails 40 secured together in any suitable manner. The end sections39 are provided with a plurality of transverse apertures 4| and outercountersunk or recessed nut-receiving sockets 42 for housing the nuts 43of tie rods 44 extended through the aligned apertures 4| of the endsections, thus permittin the end sections of the frame to snugly fit theside walls of the housing receptacle.

According to this form of the invention, the cutting knives are in theform of thin, relatively wide semi-circular knives 45 having apertures45 therein adapted to align with the apertures 4| of the end sections,and thin relatively narrow semicircular cutting knives 41 having notches48 to align with the apertures 4| and 4'5. The cutting knives 45 and 41conveniently are formed of stainless steel of 6 inch thickness orthinner, the knives 45 conveniently being about to 1 inch wide (radialwidth) and the knives 41 about to inch wide. The knives 45 and 41 areassembled between the end frames 39 in alternating relation and are tiedtogether by the tie rods 44 passed through aligning apertures 4|, 46 andnotches 48. The knives 45 and 41 are maintained in proper spacedrelation on the tie rods in spaced notches formed by suitable spacingmeans 49, for example bushings or washers.

The provision of a screen having alternately arranged narrow and widersemi-circular knives combines the advantages of a light weightconstruction, adequate rigidity and strength, while maintaining aself-clearing screen.

A slightly modified form of screen is shown in Figs. '7, 8 and 9 whereinthe semi-circular end sections 50 may be of flanged construction, forexample angles in cross-section, providing a flange 5| and web 52, theend sections 50 being tied together by side rails 40. The webs 52 of theend sections 50 are formed with a series of non-circular openings 53 toreceive correspondingly shaped reduced ends 54 of spacer bars 55, theshoulders 56 of the bars at the reduced ends 54 serving to maintain theend frames in proper spaced relation. The spacer bar 55 may bemaintained in assembled relation with the end section 50 by means of apin 55 passed through aperture 51 in the reduced end 54 of the bar.

The spacer bars 55 are provided with a series of notches 58 throughouttheir length, which are of a width to receive the semi-circular knives59 which are notched as at 60, providing a mortised joint between thespacer bars and cutting knives. The ends of the semi-circular cuttingknives may be securely held in the frame by a rod 6| passed throughopenings 62 in the knives at the end frames.

The spacer bars 55 advantageously may be in the form of cutting bars,being provided with knife-edged sections 55 interposed between thesemi-circular knives 59. Preferably the cutting edges of the knife edgesections 55 extend slightly above the upper edges of the knives 59 asshown in Fig. 9, and the knives may be inclined forwardly from a radialposition toward the advancing rotor blades to aid in effectivelyshredding the material.

A further modified form of screen is shown in Fig. 10. According to thismodification of the invention the transverse semi-circular knives may becomposed of a plurality of straight bars 59 connected betweencircumferentially spaced tie rods 44 between the end frames 50 andproviding segmentally arranged cutters. If desired, other cutters 63 ofwire may be interposed between the adjacent cutters 59 where extremefineness of the shredded material is desired.

In operating the machine, the rotor is set in motion at a desirablespeed, for -example 1800 R. P. M. The material to be shredded, i. e. thecitrus cannery waste comprising the whole culls, the half or quartersections of peel with the rag or seed is fed to the machine through theinlet 14 above the receding side of the rotor which is rotating in thedirection of the arrow, Fig. 3. The waste is immediately engaged by therotor blades and is cut into narrow threads, particularly whenrelatively thin blades are used. In any event the material is carried bythe blades 21, particularly the outer notched ends thereof, and iscarried down over the spaced semi-circular cutting blades of the screenthrough which the material is forced by the centrifugal force of therotating rotor.

Some of the material may not be forced through the screen but will becarried around past the screen by the blades 21. This material is thusengaged by an arcuate plate section 10 one end of which is hinged as atH to the top [2, and the other end being free to move by gravity towardthe rotor blades. The movement of the free end of the plate section 10inwardly toward the rotor blades 21 is preferably limited by suitablemeans such as a pin 13 on the plate sliding in a slot 14 in the coverl2. The plate thus presses the material carried past the cutting screeninwardly toward the axis of the rotor insuring that it will be carriedaround to the inlet throat l4 so that it may again be subjected to thecutting screen under the centrifugal force of the rotor.

The size of the pieces of shredded waste may be varied considerably bythe selection of the type of rotor blade used. When thin blades formedwith sharpened cutting edges are used, the citrus waste material isinitially cut by the rotor blades principally to force the materialthrough the cutting screen.

From the above it will be seen that I have provided a machine that cutsthe citrus waste pulp into shreds instead of beating it into particlesas in the case of hammer mills heretofore use. As a result, I am able toshred citrus pulp at about one-sixth the power required for conventionalhammer mills operating at the same tonnage rate. The more uniform sizeof the shreds makes possible a more uniform and easier drying of theshredded waste.

My invention is not to be restricted to the particular details shown anddescribed, which are intended merely as illustrations of the invention,and the scope of the invention is best defined in the appended claims.

1. A screen for a vegetable pulp shredder comprising a substantiallyrectangular frame having longitudinal side rails and substantiallysemicircular end rails connected thereto, a plurality of spaced tie rodsbridging the space between said end rails and including a side tie rodlocated closely adjacent each side rail, some of said tie rods having aplurality of spaced notches, a plurality of thin, relatively widesmooth-edged cutter blades of a thickness not exceeding approximatelyinch supported by said tie rods between said semi-circular end rails andhaving portions thereof positioned in said notches, said cutter bladesbeing spaced apart longitudinally to provide narrow elongated openingstherebetween disposed circumferentially to the line of feed to saidscreen.

2. A screen as defined in claim 1 further characterized in that each ofthe cutter blades is provided with an aperture adjacent one end thereofand a tie rod is extended through said aperture and said end rails toremovably mount said cutter blades on said frame.

3. A unitary screen assembly for a vegetable pulp shredder comprising asubstantially rectangular frame having longitudinal side rails andsubstantially semicircular end rails connected thereto, a plurality ofspaced tie rods bridging the space between said end rails and includinga side tie rod located closely adjacent a side rail, a plurality ofrelatively wide cutter blades supported edgewise between saidsemi-circular end rails and being secured at one end to said side tierod and having interlocking engagement with at least one of said othertie rods, said cutter blades being spaced apart longitudinally toprovide narrow elongated openings therebetween disposedcircumferentially to the line of feed to said screen, said cutter bladesfurther being of relatively thin material of approximately inch or lessin thickness and having substantially smooth upper cutting edges wherebymaterial fed to said screen is uniformly cut into elongated strips.

4. A screen as defined in claim 3 further characterized in that thecutter blades are of different radial widths to prevent clogging of thescreen.

5. A screen as defined in claim 3 further characterized in thatalternate cutter blades are of differentwidths to prevent clogging ofthe screen.

6. A screen as defined in claim 3 further charecterized in that thecutter blades are straight sections supported at their ends by tie rods.

DANIEL B. VINCENT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Emmott et a1 Jan. 31. 1911 15 Number NumberName Date Boero Mar. 2, 1915 Armstrong Feb. 1, 1916 Stoner July 1. 1930Levin Jan. 6, 1931 Bare] Oct. 10, 1933 Ossing et al Dec. 27. 1938 DimOct. 1, 1940 Thomas Mar. 30, 1943 FOREIGN PATENTS Country Date, GreatBritain Jan. 31. 1911 Germany Sept. 14, 1932

